This invention is directed to an electronic timepiece with a global time display, and in particular to a global time display timepiece that is selectively disposable between a local time mode, wherein the time for a predetermined local time zone is displayed, and the local time zone indicated, and a global display mode, wherein the numerical display digits display time in different global time zones and indicate the particular time zone being displayed.
Initially, electronic wristwatches capable of providing indication of the time for each of the twenty-four global time zones were mechanical or electro-mechanical hand display wristwatches. Such wristwatches were characterized by a circular scale representative of each of the global time zones with a location within each time zone being designated on the circular scale, in order to permit the wearer of the wristwatch to readily identify the particular time for that time zone. Selection of global time zone information was obtained by manually rotating the circular scale with respect to the hands display.
Although digital display global timepieces, wherein numerical display digits are provided for displaying the time in more than one global time zone have been provided, such timepieces provide less than completely satisfactory correction of the time displayed thereby. Specifically, instead of permitting time correction to be effected in the time zone that is being displayed by the timepiece, the time, at a particular reference time zone, such as the latest time zone, is selected for correction, and thereafter the difference in the time between respective time zones is added to the time at the reference time zone. Thereafter, each of the remaining counters must be adjusted to take into account the time at the referenced time zone. An apparent disadvantage of this type of arrangement is that the latest time zone will often be on a different day and can even be in a different month, year, etc., than a particular global time zone for which time correction is being sought, thereby requiring an unusually large number of carry digits having to be transferred between series connected counters to accommodate for the date, year and month changes. Accordingly, an electronic timepiece with a global digital display, that permits correction in each of the global time zones capable of being displayed, is desired.